Universal Windows Revives 'Three Screens and a Cloud' Strategy

Microsoft brass has promised that Windows users will be able to compute seamlessly across their phones, PCs and TVs since 2009. That vision, which the 'Softies came to call "three screens and a cloud," still has yet to materialize.

Many company watchers wrote off Microsoft's grand cross-platform plan as an impossible dream, if not outright failure. It seems, however, Microsoft management still has the goal in its sights and are finally in a position to make "write once and run on any Windows" a reality.

Part of the reason three screens and a cloud goal still hasn't materialized is the underlying infrastructure required didn't exist (and still doesn't). But it's getting closer. And rather than a "three screens" initiative, Microsoft's updated plan is to enable any device with a Windows core to sync and share.

This expanded three-plus-screens vision means that Microsoft is gunning to enable application and service sharing across everything from Internet of Things-embedded devices, to phones, phablets (tablets which also function as phones), tablets, PCs, large-screen displays (such as Perceptive Pixel) and entertainment consoles. To pull it off, Microsoft needs to put in place a common OS core, a common set of development tools, a common app store and a way for developers to reuse more of their code in creating a common set of apps.

It's this last piece -- universal Windows apps -- that was a big focus at the Microsoft Build conference last month. By building universal apps, developers can reuse more of their code when targeting different Windows platforms and flavors.

Universal Windows apps require a new version of the Windows Runtime (WinRT) that isn't the same as the Windows Runtime currently in Windows Phone, nor the Windows Runtime that's currently in Windows 8.x. The new Windows Runtime is inside the Windows Phone 8.1 and Windows 8.1 Update OS releases. To build these apps, developers also need Visual Studio 2013 Update 2, which was still in preview/test form as of Build in early April.

Universal apps will still require some customization specific to the device type/size, UI and underlying hardware. But Microsoft execs are saying devs will be able to reuse anywhere from 51 percent of their code or more, with more being likely the majority.

The next step on the road to three screens is the ability to get these universal apps running on the Xbox. Microsoft officials at Build noted this is on the roadmap, but didn't provide a target date when developers will be able to do this. Given Xbox One OS was built on top of the Windows 8 core, I'd think isn't farfetched that this could be possible within a year, if not sooner.

While Microsoft officials have been focused, if not obsessed, with getting the big-brand consumer-focused apps on Windows 8 and Windows Phone, the three-plus screens scenarios don't just apply to Facebook, Pinterest, Foursquare and Instagram. Microsoft also is continuing its push, which began at last year's Build, to bring .NET developers back into the fold. Microsoft is introducing tools and technologies to try to encourage line-of-business app developers to convert their apps into Windows Store (also known as Metro-style) variants. The company also is going to release a new version of Windows Presentation Foundation (WPF) at some point, signaling that desktop (as opposed to Windows Store) apps still have a future -- something that didn't seem likely or possible just a couple of years ago.

There are still some missing pieces needed to make "Write once, run on any Windows" a reality. A common Windows Phone/Windows Store is coming, but isn't here yet. I wonder if the common store will embrace Xbox; I'd think that would be a goal. Microsoft must continue to provide guidance and tools to existing Win32 and .NET developers to get them interested in writing new apps for all Windows-based platforms, as well as to enable existing Win32 apps not to be siloed. And while OneDrive is a good start, the cross-Windows cloud story still needs filling out.

One Windows is finally on its way to being more than just a feel-good slogan.

Mary Jo Foley is editor of the ZDNet "All About Microsoft" blog and has been covering Microsoft for about two decades. She's the author of "Microsoft 2.0" (John Wiley & Sons, 2008), which examines what's next for Microsoft in the post-Gates era.